Annuals or perennials, varying in habit but usually tufted. Leaf-sheath ± coriaceous, usually open, except near base. Ligule a rim of minute hairs, very rarely membranous. Leaf-blade narrow, flat, involute or convolute. Inflorescence an open or contracted, spiciform or glomerate panicle. Spikelets solitary, pedicelled, rarely sessile, usually laterally compressed, or subterete, 3-many-flowered, florets usually closely imbricating, disarticulation above glumes and between lemmas, or glumes and lemmas deciduous but paleas ± persistent. Glumes ± unequal, < lemmas, usually membranous, keeled, acute or acuminate; lower shorter, 1-nerved, upper 1-(3)-nerved. Lemma membranous to chart-aceous, keeled or rounded, 3-nerved with lateral nerves ± obscure, obtuse to acuminate, entire or rarely mucronate. Palea ≈ lemma, 2-keeled, keels sometimes ciliate. Lodicules 2, small, ± fleshy. Stamens (2)-3. Ovary glabrous; styles free; stigmas plumose. Caryopsis ovate-oblong or cylindric, sometimes angled; embryo to ½ length of caryopsis or longer; hilum basal, punctiform. Chasmogamous or cleistogamous. Fig. 21.